1. Field of the Invention
The present invention relates to high quality foodstuff compositions capable of imparting good cohesion and additional nutrient values to protein substances, to the products similar to meat which contain such compositions, as well as to the process for obtaining the said products simulating meat, including meat substitutes.
2. Description of the Prior Art
Meat substitutes are prepared in accordance with any one of a number of different texturizing methods from vegetable or animal proteins, such as those extracted from, for example, soya beans, sunflower seeds, horsebeans, peas, peanuts or milk casein. The methods most commonly used for converting crude proteins into more elaborate products useful as meat substitutes are extrusion and spinning.
By "spinning" there is intended a process for forming threads by extruding a solution, a dispersion or a gel through a plate provided with small diameter orifices, or spinneret, of appropriate shape and size. The products obtained according to the spinning process are referred to as threads, filaments and/or fibers, and a combination of such filaments is referred to as a bundle. Spinning offers the advantage that it reproduces the fibrous nature of the meats and makes it possible to obtain a variety of products in respect of their appearance and their nutrient properties. However, it necessitates the use of purified proteins, such as isolated protein products, which typically are powders containing more than 90% of proteins. In fact, products containing less than 70% of proteins cannot be directly spun.
In order to be spun, the proteins must first be converted into a protein gel; in the present text, the term "protein gel" or "collodion" will denote a dispersion of isolated protein products in an appropriate dispersing medium, such as an alkaline solution; the said dispersion can reach the point of forming a colloidal solution, depending on the type of proteins dispersed and on the dispersing agent employed.
The filaments obtained by spinning are coagulated in an acid and/or saline bath and are then drawn, neutralized and washed. Such technique provides bundles of filaments of different thicknesses, depending on the number and diameter of the holes of the spinneret. Coagulation fixes or sets the structure of the filaments and drawing, by orienting the filaments, makes it possible to vary their softness or their hardness. However, in order that the proteins thus molded or shaped simulate meat as closely as possible (the term meat, within the scope of the invention, encompasses both mammalian flesh and the flesh of birds, fish, crustaceans and other animals which man consumes for his nourishment), it is essential to have, in addition to the fibrous character, a certain texture and consistency which provides the sensation, which is difficult to reproduce, of "chewing" in the course of the ingestion of the product, as well as providing all the flavor of animal flesh. It thus proves necessary to impart to the proteins the cohesiveness and texture of the natural products sought to be reproduced.
It has also been proposed to bond the protein fibers to one another by means of ovalbumin (or egg albumin) used either by itself or mixed with other compounds.
Ovalbumin, used as the sole binder, has successfully fulfilled its function, but for certain preparations which require heating and rehydration it has not proved entirely satisfactory because the product obtained has a floury and looser appearance than a natural meat.
Furthermore, it is a relatively expensive product while one of the objects of the preparation of meat substitutes is, precisely, to obtain inexpensive proteinaceous materials.
Ovalbumin has been introduced into binder compositions containing other ingredients. Thus, it has been proposed to impregnate the protein fibers with a ternary composition consisting of albumin, gluten and defatted oleaginous seeds (cf. U.S. Pat. No. 3,343,963).
Other compounds have also been mentioned as possible binders, namely, gelatin, casein, wheat flour or soya flour, and solids based on dried milk (compare French Pat. No. 1,048,464). Finally, in addition to the products above mentioned, the starches, the alginates and the pectins can also be used as binders.
Some of these compositions suitably fulfill their function as a binder for protein fibers, but neither the texture of the final product obtained nor, above all, the nutrient properties of the binder, are optimized.
Accordingly, a great need exists for a meat substitute, based on proteins, in particular on vegetable proteins, which exhibits nutrient properties and a protein balance equivalent to or even superior to those of animal meat.